db1021 is experiencing more "Too many connections" bursts than its
siblings in s5. The only obvious difference is it still runs 5.5.34
while the others have already upgraded to 5.5.36. Reduce db1021 load
until a new slave can be cloned and db1021 depooled for upgrade.

Change-Id: Ia1594f9ff2da2a77523470751b89171113abcca0